Lowercase \mathcal

Question

The standard font used for \mathcal does not include any lowercase characters. The Comprehensive LaTeX Symbols List suggests redefining \mathcal to use Zapf Chancery. However I do not particularly like that font. For example the uppercase "I" is very hard do distinguish from the non-mathcal "I". Are there any good alternatives?

Answer 1

I'm a bit surprised that Will Robertson hasn't dropped by and mentioned the STIX fonts as these have the lowercase calligraphic (and lowercase blackboard bold) glyphs.

There doesn't yet seem to be a simple LaTeX package available mapping all the glyphs to particular commands, though. The stix package on CTAN at present seems to be just a copy of the fonts themselves (reorganised into correct texmf tree layout) but no style files as yet. I recall reading on the STIX website that LaTeX-related stuff was intended, but given how long it took the fonts to be released, I'm not holding my breath!

---

As of 2018, this is now quite easy using luatex or xetex:

\documentclass{article}
%\url{https://tex.stackexchange.com/q/479/86}
\usepackage{amsmath}
\usepackage{fontspec}
\usepackage{unicode-math}
\setmainfont{TeX Gyre Pagella}

% Any of the following work, and probably many more
%\setmathfont{TeX Gyre Pagella Math}
%\setmathfont{TeX Gyre Termes Math}
%\setmathfont{STIX}
\setmathfont{Asana Math}

\begin{document}
\begin{gather*}
{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
{abcdefghijklmnopqrstuvwxyz} \\
\mathcal{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
\mathcal{abcdefghijklmnopqrstuvwxyz} \\
\mathscr{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
\mathscr{abcdefghijklmnopqrstuvwxyz} \\
\mathbb{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\
\mathbb{abcdefghijklmnopqrstuvwxyz} \\
\end{gather*}
\end{document}

As pointed out in the comments, you need to use \mathscr (or \let\mathcal=\mathscr).

Answer 2

A lowercase L can be done with \ell. But this seems to be the only lowercase letter that is included without loading any packages.

Answer 3

The font package boondoxo has both lowercase and uppercase calligraphic math symbols, as well as their bold versions. You may load it by \usepackage[cal=boondoxo]{mathalfa}, and see whether you like it.

Answer 4

symbols suggests using the calligra package as an alternative to Zapf Chancery. Put

\DeclareMathAlphabet{\mathcalligra}{T1}{calligra}{m}{n}

in the document’s preamble to use \mathcalligra for calligraphic symbols in the Calligra font.

/EDIT: To be honest, I’m not thrilled by the result, and I expect you won’t be either. Still, I’ll leave this here. Perhaps someone can profit from it.

Answer 5

Two solutions that work in standard LaTeX, unlike above.

Solution 1: dutchcal = very calligraphic letters. Add this line to the preamble:

\usepackage{dutchcal} % \mathcal: also small letters. \mathbcal = bold ones. 

Very calligraphic (just c,o not clearly non-normal, but the meaning of FIJQTZnrswz may be unclear to reader, as they are so non-normal, unless guessable from the context). Usage:

$\mathcal{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\\ 
\mathcal{abcdefghijklmnopqrstuvwxyz} \\\\ 
\mathbcal{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\\ 
\mathbcal{abcdefghijklmnopqrstuvwxyz}$

Solution 2: pzccal = only somewhat calligraphic. I,O & some lowercase letters not clearly nonnormal unless next to their normal peers:

\usepackage{pzccal} % \mathpzc (alternate mathcal): also lowercase.
\DeclareFontFamily{OT1}{pzc}{}
\DeclareFontShape{OT1}{pzc}{m}{it}{<-> s * [1.10] pzcmi7t}{}
\DeclareMathAlphabet{\mathpzc}{OT1}{pzc}{m}{it}

Usage:

$\mathpzc{ABCDEFGHIJKLMNOPQRSTUVWXYZ} \\ \mathpzc{abcdefghijklmnopqrstuvwxyz}$

I'd go with solution 1 if the clarity seems sufficient from the context, else solution 2.

Found here: https://latex.org/forum/viewtopic.php?t=29074

Answer 6

Think about meaning. Mathematical symbols are symbols used by mathematicians to carry a particular meaning (which may depend on the subject area). Unicode takes that point of view (more-or-less) by giving each distinct mathematical symbol its own code point.

Typographically, a calligraphic F is an 'F' in a particular font, but mathematically it is mathematical symbol with its own meaning. Ordinarily Unicode does not care about the font, but for math symbols it does.

In my experience, mathematicians don't use lower-case calligraphic symbols, and as far as I know there are no Unicode code points for them. Put another way, Knuth did not create lower-case mathematical calligraphic letters because mathematicians don't use them.

As a mathematician, I don't see a sufficiently good reason to start using them.